1 Division of Rheumatology, Department of Medicine, University of Alberta Hospital, Edmonton, Alberta, Canada.
2 Department of Rheumatologic and Immunologic Disease, Cleveland Clinic, Cleveland, Ohio.
3 Department of Dermatology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
4 Division of Rheumatology, Department of Medicine, Inflammation and Immunity Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.